Thermic siphon



B. E. LARSON THERMIC SIPHON 2 Shets-Sheet 1 Filed Feb. 1'7,

Ap 5, 1932. a. E. LARSON- THERMIC SI'PHON Filed Feb. 17. 1930 2 Sheets-$heet 2 Q Q Q. Q Q Q Q Patented Apr. 5, 1932 UNITED STATES PATE NT err-ice BERT E. LARSON, OF PARK RIDGE, ILLINOIS, ASSIGNOR TO LOCOMOTIVE FIREB'OX COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF DELAWARE THERMIC SIPHON Application filed February 17, 1930. Serial No. 429,014.

This invention relates to improvements'in thermic siphons and it consists of the matters hereinafter described and moreparticularly pointed out in the appended claims.

The thermic siphon with which my invention is concerned is a flat hollow water wall disposed in the firebox of a locomotive type of boiler and it is connected at its discharge end in the crown sheet and has a tubular neck at the other end fixed in the throat sheet. Its function is to increase firebox heating surface thus gaining greater water steaming and circulation eficiencies. Such a siphon and the many advantages gained by its use is best set forth in the Nicholson Patent 1,337,720 issued April 20, 1920.

Siphons are of different outline shapes, the shape of course being determined by the firebox in which the siphon is installed. In some instances, the siphon may be said to be substantially triangular and the bottom of such a siphon extends in an approximately straight line in an inclined plane from the throat sheet to the crown sheet and such a 5 siphon has become known in the railroad industry as a plain siphon. 'Again in other instances the bottom of the siphon extends in an inclined plane and the rear end of the siphon extends in another plane of greater inclination and said bottom and end of the siphon are connected together by a curved corner portion. Such a siphon is best shown in the Nicholson Patent $81,679,051 issued July 31, 1928. Due to this curved corner portion, such a siphon has become known'in the railroad industry as a bull-nose siphon. Both the plain and the bull-nose siphon have a common trait in that the bottom of each is defined b a bulged portion forming a continuation of the tubular intake or inlet neck and thisbulged portion is of a transverse dimension greater than that of the spacing of the side walls. This bulge isalso advantageously employed as a supporting shoulder for the bricks of the arch when such an arch is used in connection therewith.

In the plain siphon, the bulge dies out as it approaches the discharge end fixed in the crown sheet and when a brick arch is employed therewith a peculiar objection developsQ If the brick arch is as long as the bulge, then the rear-most brick comes so close to the crown sheet as to materially obstruct the flame passageway to the .flues. With such a restricted flame passageway the products of combustion roar through the same and the'intense heat thereof is localized upon such a small area that the rear-most brick fuse together as 'a mass. Again the abrasive action of said products of combustion quickly erodes these bricks so that the arch disintegrates. If it is attempted to over come this objection by omitting the rearmost brick, then the arch is too short@ With the bull-nose siphon, the bulge stops or dies out at the corner or nose and the re maining rear end of the siphon, including the curve or nose, is reduced in width or cross sectional dimensions to that. of the body. As the bulge is employed to support the arch, it is apparent that the arch terminates at its rear end just forward of the corner or nose. Thus the rear end of the arch is spaced a greater distance below the crown sheet so that a flame passageway of greater area is produced above the arch between the associated siphons and this greater area is gained without reducing archlength.

While this bull-nose. siphon gives greater areas of flame passageway above the arch without sacrificing the length thereof, it has been demonstrated in use that the nose receives a terrific bombardment by the products of combustion as they enter the flame passageways above the arch and as the nose is of a width equalling that of the body only, the metal of the nose tends to burn off because there is not enough water behind the same to take up all the heat units imparted to the nose.

My invention is particularly concerned with'the last mentioned typeor bull-nose si- .phon and the main object'of the invention is to provide a siphon ofv this kind so formed that the cross sectionalarea of the nose ismaterially increased to provide that water backing necessary to absorbthe heat units imparted thereto, whereby the metal of the nose more readily stands up under bombardment d 7 and therefore has a greater period of usefulness.

Another object of the invention is to provide a siphon of this kind wherein the bulge is extended around and beyond the nose to provide greater water backing for the nose.

Still a further object of the invention is to provide a siphon of this kind wherein the nose is made on a curve or are of greater radius than heretofore, which makes it possible to form the bulge around the curve without any undue buckling or stretching of the metal at this point.

These objects of the invention as well as otherstogether with the many advantages thereof will more fully appear as I proceed with my specification.

In the drawings Fig. 1 is a longitudinal vertical sectional view through the firebox end of a locomotive boiler of the combustion chamber type embodying my invention.

Fig.- 2 is a transverse vertical sectional view through the same on an enlarged scale as taken on the line 2-2 of Fig. 1.

Figs. 3, 4 and 5 are detail transverse vertical sectional views each on an enlarged scale as taken on the lines 33, H, and 55, respectively of Fig. 1.

Fig. 6 is a view in side elevation on an enlarged scale of the rear end portion of a bull-nose siphon embodying my invent on.

Referring now in detail to that embodiment of the invention illustrated in the accompanying drawings and especially to Figs. 1 and 2 thereof which show a substantially long locomotive boiler firebox of the combustion chamber type, 1 indicates as a whole the firebox of the boiler, which includes a combustion chamber 2 at the front end thereof. Said firebox includes, the usual back sheet 3, flue sheet 4 and crown sheet 5 extending from the back sheet to the flue sheet. 6 indicates the side sheets of the firebox. 7 indicates the bottomv of the combustion chamber and 8 indicates the inner sheet of the front throat, which sheet joins with the bottom of the combustion chamber. As the other sheets of the boiler are disposed and correlated with respect to the sheets of the firebox, just above mentioned, in the manner well known, it is not believed necessary to describe them in detail.

' In the firebox proper is located one or more siphons 9-9 and in the combustion chamber .is one or more siphons 10-10, disposed in vertical planes intermediate those of the siphons in the firebox.

Each siphon 9 which is of a somewhat irregular rectangular shape when viewed in side elevation comprises a pair of laterally spaced, upright side walls 1111 joined together at the front end of the siphon by a substantially perpendicular rounded end wall 12. The side walls of the siphons are stayed together as is well known in siphons of this kind. The bottom of the siphon is formed by a bulged portion 13 having a front end tubular extension 14 that is formed on a curve of a generous radius, the extremity of said neck being secured in a flexible diaphragm 15 formed in the throat sheet 8. Said bulged bottom portion extends upwardly and rearwardly from the neck at the desired inclina tion which in this instance has a shallow angularity. The rear end 16 of the siphon is disposed at an angle much greater than that of the bulged bottom 13 and is joined thereto by a curved portion or corner 17 made on an arc of a generous radius and this curved portion forms the nose of the siphon whereby a siphon of this kind receives its name as before mentioned. 7.

Heretofore in the bull-nose type of siphon, the rear end 6 of the siphon wasdisposed at a greater angle, in fact this angle approached substantial parallelism with that of the front end 12 and consequently the nose or-corner was made upon a curve of a much smaller radius. It is pointed out at this time that the siphon is made from a single sheet of metal cut to pattern form and then folded longitudinally upon itself in a machine especially made for this operation, after which the edges were Welded to make up the finished siphon. In making the curve or bend for the nose, the excess metal had to be displaced and this excess metal went into the nose as is shown in dotted lines at 18 in Fig. 6 and gave a much steeper angle to the rear end and a much smaller radius for the curve or corner for the nose. With suchan arrangement it is not only impractical but well near im possible to continue the bulge around this curve with a result that it is terminated at the beginning of the curve or corner where it gradually merged into the flat sides of the siphon. Thus the cross sectional area of the siphon was the same at the corner as it was through the body.

As the bulge terminated at the corner, the brick arch there also terminated sothat a flame passage was provided which was defined at the top and bottom by the crown sheet and arch and at the sides by adjacent siphons where more than one siphon was disposed in the firebox. Thus it is apparent that the nose of the siphons was so located with respect to the flame passage mentioned that it received the brunt of'the bombardment by the products of combustion and was disposed in the Zone of highest temperature. With but a comparative narrow water column backing up the nose, it'was not sufiicient to absorb I have overcome the objections in the following manner. I reduce the angularity of of the rear end as at 13 where it then dies down to merge into the side walls at this point.

In forming the bulge up around and be yond the nose, that excess metal which develops in the initial producing of the nose as before described in connection with the dotted lines showing in Fig. 6, and which in reality determined the shape and size of the nose, is cutaway in a plane between the side walls to form a dart like opening. The metal adjacent said opening is then drawn and worked inward to close said opening. This removesthe excess metal whereby the angle of the rear end 16 is lessened so that the curvature of the nose can be made on a greater radius and this permits the formation of the bulge to be carried up around and beyond said nose. In forming the metal to produce this bulge, the curvature of the nose is of such radius that there is room enough for the metal of the bulge without causing a buckling or wrinkling along the inner portipn thereof and therefore the character of the metal of the nose is not so changed as to break down under the stresses and strains due to temperature changes.

With the construction described the nose is backed up by a column of water of greater cross sectional area whereby the terrific heat imparted ,to the nose as the products of combustion impinge against and passes around the same, is more readily absorbed by said water column so that burning out and rapid wear is Very materially reduced. Again the nose being made on the larger and more gradual curve as described, the water as it rushes up through the siphon follows along the bulge and sweeps the interior surface of the nose clean of all sediment so that heat transmission is increased at said nose. Again with the more gradual curvature mentioned there is no tendency to produce a turbulence or eddy of water in the nose and all of these advantages materially increase the life of the siphon. It is also pointed out that this arrangement provides a larger flame passageway above the rear end of the arch and this without reducing the same in length, from the rear end thereof. I

The siphons 10-l0 in the combustion chamber are substantially Y-shaped when viewed in side elevation. Each siphon includes a substantially triangular fiat hollow body 19 the open top end of which is fixed in the crownsheet and connected to the bottom end of the body is a tubularintake neck 20 which opens through the bottom wall 7 of the combustion chamber in the manner well known in combustion chamber siphons.

While in describing my invention, I have referred in detail to the form, arrangement and construction of the parts thereof, the same is to be considered merely as illustrative so that I do not wish to be limited thereto except as may be specifically set forth in the appended claims.

I claim as my invention 1. A siphon of the kind described embodying therein a flat hollow body having a closed bottom and a closed end disposed at an angle with respect to said bottom and connected thereto by a corner portion of substantial curvature, said corner portion having a cross sectional width greater than that of said body.

2. A siphon of the kind described embodying therein a flat hollow body having a closed bulged bottom and a closed rear end disposed at an angle with respect to said bottom and connected thereto by a bull nose like corner portion, said corner portion also being bulged with a cross-sectional width greater than that of said body and substantially equal to that of the bulged bottom of the body. 7

In testimony whereof, I have hereunto set my hand, this 14th day of February, 1930.

BERT E. LARSON. 

